Process of annealing copper wire



UNITED STATES PATENT OFFICE.

WILLIAM WALLACE AND THOMAS J. WOOD, OF ANSONIA, CONNECTICUT.

PROCESS OF ANNEALING COPPER WIRE.

SPECIFICATION forming part of Letters Patent No. 312,045, dated February 10, 1885.

Application filed November 26, 1884. (No specimens.)

To all whom it may concern.-

Be it known that we, WILLIAM WALLACE and THOMAS J. W001), of Ansonia, in the county of New Haven and State of Connecticut, have invented a new Improvement in Processes of Annealing Copper Wire; and We do hereby declare the following to be a full, clear, and exact description of the same.

This invention relates to an improvement in processes of annealing copper wire-that is, wire made from copper and its alloys, and such as used for electrical purposes, and which must necessarily be inits softest possible condition. Under the usual process of annealing, the surface is oxidized to such an extent as to form a considerable scale, which scale must be removed by pickling or otherwise before it is in a merchantable condition. The scale is irregular in its thickness, due to the variation of heat at different points. The removal of the scale, therefore, makes irregularities or reduces the size of the Wire, causing a defect where perfect uniformity is desirable, as in electrical work.

The object of our invention is to avoid the scale heretofore produced in the annealing process; and it consists in packing the wire in pots with oxide of copper.

1n carrying out our process we employ the common annealing-pot, removing the coils of wire from the blocks in the usual manner, place first a layer of oxide of copper at the bottom of the pot, then a coil of wire, cover it with oxide of copper, then another coil, then a covering of oxide of copper, and so on alternately a coil of wire and afilling of oxide of copper. The pot thus filled is placed in the annealing-furnace, and there subjected to heat for, say, one hour, more or less, according to the size of the wire. At the proper time it is removed from the pots in the usual manner.

While the surface of the wire will be slightly discolored, it does not lose its luster in the process of annealing, and may be put upon the market in that condition. If, however, a clear surface is desirable, the wire may be pickled; but as there is no scale produced in the process of annealing, such pickling or cleaning will not reduce the diameter or change the surface of the wire. The Wire, therefore, coming from this annealing process has the same uniform diameter and surface as when it comes from the block.

If the wire annealed under our new process be pickled to give it a clear surface, that surface will be much brighter than in the old process, where the scale is removed by pickling. The wire, therefore, is readily distinguishable from that produced under the old method of annealing.

We claim- The process herein described for annealing wire made from copper and its alloys, consisting in packing the coils of wire in pots with oxide of copper, and while so packed subjecting it to heat in the annealingfurnace, substantially as described.

WM. WVALLACE. THOMAS J. \VOOD.

Witnesses:

W. G. BARCLAY, W. N. BRIGGS. 

